The invention relates to a brake disk and to an axle hub for the brake disk.
A brake disk of a xe2x80x9ctwo-partxe2x80x9d construction is known from German patent document DE 195 44 559 C1. For connecting the brake disk with the hub, in German patent document 195 44 559 C1, intermediate elements are provided in the case of this brake disk for transmitting the torque and the power from the cams of the hub to the support elements of the disk, which intermediate elements can be fastened, for example, by bolts on the cams of the hub. In this case, on the one hand, the cams of the hub engage in the intermediate elements and, on the other hand, the intermediate elements engage in the support elements so that a reliable torque transmission is ensured from the brake disk to the hub in both rotating directions.
The brake disk of German patent document DE 195 44 559 C1 has been found successful per se, but a further minimizing of the temperature insensitivity of the brake disk at high stress is desirable. Particularly, the tendency of the brake disk to form cracks is to be reduced.
A brake disk and an axle hub of the above-mentioned type are known from French patent document FR 901 778. Based on this prior art, it is an object of the invention to further reduce the temperature sensitivity in the case of the brake disk and the hub. The corresponding further development of the axle hub for placing the brake disk should also be optimized.
The invention achieves this goal by means of the present invention, whose objects, viewed separately, clearly increase the stressing capacity of the brake disk and which, in their combination, supplement one another to form a particularly advantageous and highly stressable brake disk (and axle hub).
In comparison to the above-mentioned prior art, the object of the present invention is characterized in that, on the inner periphery of the brake disk, the support elements bridge the air channel in the manner of links and protrude far axially at the ratio indicated into the area of the friction rings so that the outer surfaces of the friction rings are situated at an axial distance from the outer surfaces of the support elementsxe2x80x94particularly even when exhibiting their maximally permissible state of wearxe2x80x94, the spacing of the outer surfaces of the support elements being at a prescribed ratio.
With respect to the prior art of the above-mentioned type, this solution has the special advantage that the friction surfaces, which are thermally highly stressed during braking, are separated from the support elements, which are mechanically highly stressed (by the braking forces).
Although it is known from the field of rail vehicle brake disks (see German patent document DE 38 14 614 A1) to place the support elements (occasionally also called teeth) axially in the area of the air channel, the support elements being configured as knobs lengthened radially from the links of the brake disk toward the inside, this solution cannot be applied to brake disks for commercial vehicles, particularly of a weight of more than 7.5 t, because of the much higher forces occurring during the braking. It is therefore advantageous that the invention increases the mechanical stability because the support elements protrude into the friction rings.
Although it would also be conceivable to extend the support elements over the air channel axially to the outer surfaces of the friction rings, this solution has the disadvantage that high thermal and mechanical stresses would be superimposed in the xe2x80x9cfeetxe2x80x9d of the support elements, which would clearly increase the tendency of the brake disk to form cracks. As a result of the local separation of the friction surface from the exterior side of the support elements, the invention provides a clear improvement here.
A further embodiment of the invention is characterized in that the support elements are provided with feeding devices for feeding cooling air into the air channel. This embodiment also provides a clearly improved thermal behavior of the radially toothed brake disks. The brake disk is provided with an air channel formed of ribs or knobs between the two friction rings, which is known per se from the initially mentioned prior art. As a result of this variant of the invention, additional cooling air can flow through the support elements and thereby clearly increase the cooling effect of the cooling air channel. This measure therefore also provides an improved thermal behavior of the brake disk in comparison to the prior art. The feeding devices are expediently constructed as bores which extend essentially radially with respect to the brake disk.
The brake disk is preferably supplemented by an axle hub on which is placed a brake disk according to the invention, which is characterized in that the axle hub and/or an adapter, which can be inserted between the axle hub and the brake disk, is provided with hub bores or openings, which are opened radially toward the inside or laterally axially toward the outside, for feeding cooling air into the bores of the support element and/or directly into the air channel constructed between the friction rings. This further increases the cooling of the brake disk in a constructively simple manner.
Additional advantageous variants of the invention are contained in the other subclaims.
In the following, the invention will be explained in detail with respect to the drawing by means of embodiments.